The major goal of this research was to look into the mediating roles of job satisfaction and the moderating impacts of demographics in the correlation between employee performance and work environment in Addis Ababa's soft drinks, wine, and beer companies.The researcher collected data by using questionnaires and examined primary data using a combination of quantitative and qualitative research approach in this study, which followed a descriptive and explanatory research strategy. A total of 344 questionnaires were delivered to top-level, middle-level, functional managers, and other workers of the selected soft drinks, wine, and beer enterprises in Addis Ababa using stratified sampling procedures and Only 312 questionnaires were completed and returned and were taken as a valid sample.The collected data was analyzed by using SPSS Version 23 software through descriptive as well as inferential statistics. At a 95% confidence level, the result of the study indicated that work environment variables (i.e., job safety and security, physical working environment, coworker relationships, supervisor support, and working hours) have a significant and substantial impact on employee performance and job satisfaction. However, at the 95 percent confidence level, demographic characteristics dimensions (i.e., gender, age, marital status, educational level, and work experience) have no effect on employee performance and job satisfaction. At a 95% confidence level, job satisfaction has a significant mediating effect in the relationship between work environment and employee performance. But demographic characteristics insignificantly moderate the relationship between work environment dimensions and employee performance at 95% confidence level. The study suggested that companies should assess their employee pay and wage structures on a regular basis to verify that they are compatible with their talents and skill, which they are almost like other companies within the market. Employees will feel safer on their work, which is able to improve their job satisfaction and in turn results better performance from them